Treaty of Lausanne

Signed in the Swiss city of Lausanne on 24 July 1923, this peace settlement between the new Turkish state and the Allied powers formally closed the conflict that had begun with the Ottoman entry into the First World War. It replaced the harsh and never-ratified Treaty of Sèvres of 1920, fixed most of the frontiers of modern Turkey and won international recognition for the Republic of Turkey as successor to the Ottoman Empire. It also confirmed a vast exchange of populations between Greece and Turkey.

After defeat in the First World War, the Ottoman government signed the Treaty of Sèvres in 1920, which would have carved up much of Anatolia. The Turkish National Movement led by Mustafa Kemal Atatürk, based in Ankara, rejected it and fought on. Its victory over Greece in the Greco-Turkish War, including the recapture of İzmir, led to the Armistice of Mudanya in October 1922. The Allies now had to negotiate a new settlement with the Ankara government, as part of the wider partition of the Ottoman Empire.

The peace conference opened at Lausanne on 20 November 1922 and lasted eight difficult months, interrupted more than once when the Turkish delegation walked out. İsmet İnönü led for Turkey, the British Foreign Secretary Lord Curzon for the Allies, and Eleftherios Venizelos for Greece. The treaty, of 143 articles, was signed at the Palais de Rumine. Turkey ratified it on 23 August 1923, and it came into force on 6 August 1924.

Turkey gave up all claims to the former Arab provinces, including Syria and Iraq, and to Egypt, Sudan, the Dodecanese Islands and Cyprus, which Britain had held since 1878. Aegean islands more than three miles from the Turkish coast went to Greece, except Imbros, Tenedos and the Rabbit Islands. Mosul's fate was referred to the League of Nations. In place of the war reparations Turkey had demanded, Greece ceded Karaağaç in Thrace. The capitulations, the privileges that foreigners had long enjoyed in the Ottoman lands, were abolished, and a separate convention regulated passage through the Turkish Straits. Turkey and the other states that emerged from the empire shared out the Ottoman public debt.

Lausanne built on an earlier Greek–Turkish convention for the compulsory exchange of populations, under which most of Turkey's Orthodox Christians and Greece's Muslims had already been deported. Exempted were about 270,000 Greek Orthodox residents of Constantinople, Imbros and Tenedos, and about 129,120 Muslims of Western Thrace, whose rights as minorities the treaty was meant to protect.

An annexed Declaration of Amnesty granted immunity for acts committed between 1914 and 1922 for political or military reasons. It ended efforts to prosecute those responsible for atrocities including the Armenian genocide, the Sayfo and the Greek genocide. Historians including Norman Naimark and Ronald Grigor Suny have argued that Lausanne set a precedent for solving minority questions through forced transfers of population.

In Britain, Lloyd George denounced the treaty as an "abject, cowardly and infamous surrender". For Greece it ended the Megali Idea, the dream of a greater Greece including western Anatolia. The Straits regime was replaced by the Montreux Convention in 1936, and Hatay, left to French-ruled Syria, became part of Turkey following a 1939 referendum. In the United States the Senate refused in 1927 to ratify a separate Turkish–American treaty. In Turkey the treaty has also attracted conspiracy theories, including the claim, which proved unfounded, that it would expire after a century in 2023.

Our 1914 map shows the late Ottoman Empire, while our 1930 map shows the borders of the new Turkey agreed at Lausanne.